That line of code—static hasMany = [volunteers : TekUser]—gives us a Collection of
TekUser objects, along with methods to add and remove them. Grails’ dynamic
scaffolding will automatically pick up this change and modify our views. To
demonstrate this, let’s add some more bootstrap code. Open TekDays/grailsapp/
conf/BootStrap.groovy, and add the following code to the bottom of the init block: